Degassing method and system

ABSTRACT

A system and method for degassing a fluid in a syringe comprising and inserting the fluid into a negative pressure device. The system may include a holder for holding the syringe; a guide affixed to the holder; a slide for holding a plunger of the syringe, the slide being movably attached to the guide; and a locking mechanism opposite the holder for maintaining a position of the slide. The fluid degasses when the locking mechanism maintains the position of the slide. The system may also include a piercing element adjacent the holder for piercing the syringe. The system and method may also be used for removing fluid from a negative pressure device.

BACKGROUND

1. Field of the Invention

Embodiments of the present invention relate to degassing methods andsystems and, in particular, to methods and systems for degassing a fluiddisposed in a standard syringe and for inserting a degassed fluid into anegative pressure device, such as, for example, a pump or otherreservoir.

2. Description of Related Art

The use of implantable, fluid-delivering devices in the treatment ofvarious medical conditions has necessitated requisite procedures forfilling the devices with an appropriate fluid and removing “stale” fluidfrom the devices when necessary. Although the devices themselves, suchas, for example, pumps and other reservoirs, could be surgically removedfrom a patient every time the addition or removal of fluid from thedevice is required, such an invasive surgical procedure performedmultiple times would prove traumatic and debilitating to the patient.Furthermore, these types of procedures are time-consuming and expensive.

Implantable pumps and other fluid-containing reservoirs that areimplanted into the human body typically operate as either a positivepressure device or a negative pressure device. Negative pressure deviceshave the advantage of precluding the fluid contained in the device fromleaking into the body in the event the integrity of the seals of thedevice are compromised. Because the pressure in the pump or reservoirunder which the fluid resides is negative with respect to the body,fluid would normally flow into the pump or reservoir rather than outwardfrom the device and into the body should a break in the seals occur.Thus, a negative pressure device provides an element of safety for thepatient, preventing a large, possibly toxic exposure to the fluid in thedevice if the seals of the device become compromised.

Filling an implanted, negative pressure device has typically been atwo-step procedure. First, the fluid with which the device is to befilled is degassed. Without proper degassing, gasses that have beendissolved in the fluid could resurface as bubbles in the fluid when thefluid reaches the body, a situation that could be dangerous for thepatient. Second, after degassing, the degassed fluid is inserted intothe patient. This is typically done through the skin using a needle thatinterfaces with a port on the device.

The tools that have been available for the degas and fill procedure havebeen inadequate for efficiently accomplishing the procedure. Forexample, generally, the implant fluid is drawn into a syringe anddegassed by pulling a vacuum in the syringe; however, no tool currentlyexists that that locks the plunger of the syringe in place once theplunger has been drawn back to create the vacuum. Thus, rather thanbeing able to use standard, off-the-shelf syringes, prior art solutionshave had to custom-modify parts of the syringe and use other externalparts to lock the plunger of the syringe in place once a vacuum has beenpulled. This type of solution is time-consuming, expensive andinefficient.

Also, both positive and negative pressure implant devices presentchallenges to the fill (or refill) procedure. In a positive pressuredevice, the fluid in the syringe must be at a greater pressure than thepressure existing in the device. Accordingly, the syringe used must beable to accommodate a pressure-generating apparatus to build up apresser in the barrel of the syringe.

In a negative pressure device, the fluid in the syringe will generallyflow from the syringe to the device, since the pressure in the syringeis normally greater than the pressure in the device. However, undercertain conditions, the pressure in the syringe may not be sufficientlygreater than the pressure in the device to force the fluid to flow fromthe syringe to the device. In this situation, some type of mechanismmust be used to generate enough pressure against the fluid in thesyringe to cause the fluid to flow from the syringe into the device.

SUMMARY

It is therefore an object of embodiments of the present invention toprovide a system and method for degassing a fluid in a syringe. It is afurther object of embodiments of the present invention to provide asystem and method for injecting a fluid into an implanted negativepressure device. It is yet a further object of embodiments of thepresent invention to provide a system and method for removing a fluidfrom an implanted negative pressure device.

A system for degassing a fluid in a syringe may include a holder forholding the syringe; a guide affixed to the holder; a slide for holdinga plunger of the syringe; and a locking mechanism opposite the holderfor maintaining a position of the slide. The slide may be movablyattached to the guide and the fluid may degas when the locking mechanismmaintains the position of the slide. The holder may be substantiallycircular and may accept a barrel of the syringe. The size of the holdermay be adjustable.

The guide may be a cylindrical post. The guide may include a first postand a second post. The guide may include a single post. The slide mayrotate about the single post. The slide may include a first aperture foraccepting a plunger of the syringe; a second aperture adjacent the firstaperture; a third aperture on a first side of the slide for accepting afirst post; and a fourth aperture opposite the third aperture foraccepting a second post.

The slide may also include a first aperture for accepting a plunger ofthe syringe; a second aperture adjacent the first aperture; a thirdaperture on a first side of the slide for accepting the first post; anda fourth aperture opposite the third aperture for accepting the secondpost. The slide may further include a latch for engaging the lockingmechanism. Also, a size of the slide may be adjustable.

The locking mechanism may be spring loaded. Also, the system may includea piercing element adjacent the holder for piercing the syringe. Thesystem may further include a lever hingedly attached to the holder. Thepiercing element may be affixed to the lever. A rotational movement ofthe lever may force the piercing element into the syringe. The piercingelement may be movably attached to the holder. A force applied to thepiercing element may force the piercing element into the syringe. Thepiercing element may peel away a portion of the syringe when thepiercing element is forced into the syringe. The piercing element maypierce the syringe in a manner that precludes pieces of the syringe fromseparating from the syringe.

A degassing tool for degassing a fluid in a syringe may include a holderfor holding the syringe; a guide affixed to the holder; a slide forholding and moving a plunger of the syringe; and a piercing elementadjacent the holder for piercing the syringe. The slide may be movablyattached to the guide.

The piercing element may be affixed to a lever. The lever being affixedto the holder. A rotational movement of the lever may force the piercingelement into the syringe. The piercing element may also be movablyattached to the holder. A force applied to the piercing element may thepiercing element into the syringe. The piercing element may pierce thesyringe in a manner that precludes pieces of the syringe from separatingfrom the syringe.

The degassing tool may also include a locking mechanism disposedopposite the holder for maintaining a position of the slide. The lockingmechanism may be spring loaded.

A method for degassing a fluid may include inserting a syringe into adegassing tool; drawing a fluid into the syringe; closing the syringe;retracting a plunger of the syringe to create a vacuum in a portion of abarrel of the syringe; locking the plunger using the degassing tool;expelling gas dissolved in the fluid into the vacuum in the portion ofthe syringe; and expelling the gas in the vacuum out of the syringe. Thefluid may be insulin.

The syringe may be closed with a stopcock. The plunger may be disposedin a slidable portion of the degassing tool.

Expelling a gas dissolved in the fluid into the vacuum in the portion ofthe syringe may include shaking the syringe while the syringe may bedisposed in the degassing tool. Expelling the gas in the vacuum out ofthe syringe may include opening the stopcock.

A method for degassing a fluid and inserting the fluid into a negativepressure device implanted in a patient may include inserting a syringeinto a degassing tool; drawing a fluid into the syringe; closing thesyringe; retracting a plunger of the syringe to create a vacuum in aportion of a barrel of the syringe; locking the plunger using thedegassing tool; expelling gas dissolved in the fluid into the vacuum inthe portion of the syringe; expelling the gas in the vacuum out of thesyringe; inserting the syringe into the negative pressure device; andopening the syringe. The fluid may be insulin and the plunger may bedisposed in a slidable portion of the degassing tool.

Expelling gas dissolved in the fluid into the vacuum in the portion ofthe syringe may include shaking the syringe while the syringe may bedisposed in the degassing tool.

The method may further include piercing a portion of the barrel of thesyringe. The portion of the barrel of the syringe pierced may beadjacent the fluid and opposite the implanted device. The barrel of thesyringe may be pierced such that no pieces of the barrel dislodge intothe fluid.

A method for filling a negative pressure device may include inserting asyringe into a degassing tool; closing the syringe; retracting a plungerof the syringe to create a vacuum in a portion of a barrel of thesyringe; locking the plunger using the degassing tool; inserting thesyringe into the negative pressure device; and opening the syringe.Also, the syringe may be inserted into the negative pressure deviceusing a needle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a generalized view of a degassing tool according to anembodiment of the present invention.

FIG. 2 shows a generalized view of a degassing tool according to anotherembodiment of the present invention.

FIG. 3 shows a generalized method for using a degassing tool to degas afluid and refill a negative pressure reservoir according to anembodiment of the present invention.

FIG. 4 shows generalized method for using a degassing tool to removefluid from a negative pressure reservoir according to an embodiment ofthe present invention.

FIG. 5 shows a generalized view of a degassing tool according to anotherembodiment of the present invention.

FIG. 6 shows a generalized view of components of the degassing toolshown in FIG. 5 according to another embodiment of the presentinvention.

DETAILED DESCRIPTION

In the following description of preferred embodiments, reference is madeto the accompanying drawings which form a part hereof, and in which areshown by way of illustration specific embodiments in which the inventionmay be practiced. It is to be understood that other embodiments may beutilized and structural changes may be made without departing from thescope of the preferred embodiments of the present invention.

Although the following description is directed primarily toward adegassing system and method, embodiments of the present invention may beused in a variety of capacities and applications. For example,embodiments of the present invention may be used for degassing insulinor other medications. Also, embodiments of the present invention may beused to insert fluid, such as insulin or other medications, for example,into an implanted pump for delivery to patient. Embodiments of thepresent invention may also be used to remove fluid from an implantednegative pressure device, such as, for example, a pump or otherreservoir. Generally, embodiments of the present invention may beadapted for use in any type of situation that calls for degassing afluid, inserting the fluid into an implanted negative pressure device,or removing fluid from an implanted negative pressure device.

A degassing tool 10 according to an embodiment of the present inventionis shown in FIG. 1. The degassing tool 10 includes, but it is notlimited to, a holder 12 for holding the barrel of a syringe containingfluid and a slide 16 that accepts a plunger of the syringe. The slide 16may be movable along guides 18 that are affixed to the holder 12. Thedegassing tool 10 may also include, but is not limited to, a lockingmechanism 28 for attaching to a latch 22 attached to the slide 16 and,thus, maintaining the slide 16 in a locked position. The lockingmechanism 28 may be attached to a base 26 and may release the latch 22by depressing a release button 30.

According to the embodiment of the invention shown in FIG. 1, thedegassing tool 10 may also include a lever 14 that is hingedly orotherwise affixed to the holder 12. Affixed to the lever 14 is apiercing element 24.

According to embodiments of the present invention, the holder 12 may beformed into a variety of sizes and shapes. For example, the holder 12may be in the form of a cylinder, a hexagon, an octagon, or even asquare or a rectangle. According to an embodiment of the presentinvention, the holder 12 may be a simple ring.

In addition, the holder 12 may include a holder aperture 34. The holderaperture 34 may be sized such that it accepts the barrels of standard,off-the-shelf syringes that are common in the industry. The holder 12may be designed such that a distance is maintained between the syringeand the plunger adequate to hold sufficient vacuum for degassing whenthe plunger is pulled away from the holder 12 and locked by the lockingmechanism 28.

The slide 16 may also be formed into a variety of the shapes and sizes.The slide 16 may include a plunger aperture 20 that is sized to acceptthe plunger of the syringe that is in the holder 12. The slide 16 mayalso a include a handle aperture 32. The handle aperture 32 may be usedfor leverage when sliding the slide 16 away from the holder 12. Forexample, a user may insert his or her fingers into the handle aperture32 while resting his or her palm on the base 26 to obtain leverage whenpulling the plunger, which is located in the plunger aperture 20, awayfrom the barrel of the syringe which is being held by the holder 12.

The slide 16 may also include guide apertures 21 that accept the guides18 and along which the slide 16 may move. The slide apertures 21 shouldbe sized such that the slide 16 may move freely along the guides 18,which themselves may be formed, for example, as circular posts.

Although in the embodiment of the invention shown in FIG. 1, the slide16 has been designed to accommodate two guides 18, the slide 16 may bedesigned to accommodate a variety of guide configurations. For example,according to an embodiment of the present invention, only one guide maybe affixed to the holder 12 and the base 26. The slide 16 may bedesigned with only one guide aperture such that the slide is able tomove up and down the length of the guide and may also rotate freelyabout the guide. In this configuration, a syringe may be placed into theholder 12 and the slide may be rotated about the guide to meet theplunger of the syringe.

The slide 16 may be designed in a variety of ways. For example, theslide 16 need not be a rigid member. The slide 16 may be designed, forexample, as a wire that attaches to the plunger of the syringe.

The locking mechanism 28 may include any mechanism that can maintain theslide 16 in a fixed position after the plunger of the syringe has beenpulled away from the holder 12 so that a vacuum forms within theinterior of the syringe barrel. In the embodiment of the invention shownin FIG. 1, the locking mechanism 28 is a spring-loaded post thatincludes an extension 29 for mating with the latch 22. The latch 22 mayinclude one or more teeth to provide a variable lock position for theslide 16. To release the latch 22 from the locking mechanism 28, arelease button 30 may be depressed to move the locking mechanism 28 awayfrom the teeth of the latch 22. According to another embodiment of thepresent invention, the locking mechanism 28 itself may be directlypushed away from the latch 22.

The lever 14 may simply be hinged to the holder 12 or may bespring-loaded, for example. The lever 14 may be operated such thatrotation of the lever 14 forces the piercing element 24 into the barrelof a syringe that is positioned in the holder 12, thereby puncturing thebarrel of the syringe and creating an opening for venting. The lever 14may be designed with a cam or a screw, such that turning the cam orscrew would force the lever 14 toward the syringe and cause the piercingelement 24 to enter the syringe.

According to another embodiment of the present invention, the piercingelement 24 may be located directly on the holder 12 and may be used topierce the barrel of a syringe positioned in the holder 12 simply bypushing on the piercing element 24 itself. The piercing element 24 mayalso be designed with a cam or a screw, such that turning the cam orscrew would force the piercing element 24 toward the syringe and causethe piercing element 24 to enter the syringe.

The piercing element 24 may be positioned in a variety of places on thelever 14 or the holder 12. According to an embodiment of the presentinvention, the piercing element 24 enters the syringe below the plungercap but substantially close to the plunger cap so that use of the barrelof the plunger is maximized if the syringe is pierced by the piercingelement 24.

The piercing element 24 may be designed such that there are no loosepieces of the syringe resulting from the piercing element 24 beingforced into the syringe. Rather, when the piercing element 24 enters thesyringe, the syringe remains intact. According to an embodiment of thepresent invention, the piercing element 24 may be designed to “enter andscoop.” According to another embodiment of the present invention, thepiercing element 24 may be designed to “peel away” a portion of thesyringe. In other words, the piercing element 24 enters the syringe andscoops away a portion of the syringe so that loose pieces of the syringedue not fall into or contaminate the fluid in the barrel of the syringe.

A degassing tool 40 according to another embodiment of the presentinvention may be seen in FIG. 2. The embodiment of the invention shownin FIG. 2 is similar to the embodiment of the invention shown in FIG. 1except that the locking mechanism is effected by a first loop 42, asecond loop 43 and a third loop 44 that are hingedly, rotatably orotherwise moveably attached to the base 26. The first loop 42, thesecond loop 43 or the third loop 44 may be rotated about the base 26 toengage the latch 22, thereby maintaining the slide 16 in a fixedposition. The different sizes of the first loop 42, the second loop 43and the third loop 44 allow the slide 16 to be fixed into multiplepositions. Additional locking loops may be implemented if desired toaccommodate a plurality of locked positions for the slide.

Referring back to FIG. 1, use of the degassing tool 10 may includeinserting a standard size syringe into the holder 12. A plunger of thesyringe may be positioned into the plunger aperture 20 of the slide 16.The handle aperture 32 of the slide 16 may be grabbed by a user to pullthe plunger of the syringe back away from the barrel of the syringe thatis prevented from moving by the holder 12. When the slide 16 is pulledback far enough, the latch 22 will engage the locking mechanism 28,thereby maintaining the position of the slide 16 and, consequently, theplunger of the syringe. Thus, a vacuum will be formed and maintained inthe barrel of the syringe because the plunger is able to maintain itsposition after drawing a vacuum. Any fluid residing in the barrel of thesyringe may then be degassed.

The degassing tool 10 may be made from a variety of materials. Forexample, the degassing tool 10 may be made from aluminum, stainlesssteel or from various types of plastics.

A generalized method of using a degassing tool to degas a fluid andrefill a negative pressure reservoir according to an embodiment of thepresent invention is shown in FIG. 3. At step 50 a syringe is insertedinto the tool. The syringe may be a standard size, off-the-shelf syringecommon in the industry. At step 52, medication is drawn using a needlein the syringe such that the medication fills the barrel of the syringe.The medication may be insulin or some other fluid. Steps 50 and 52 maybe interchanged if desired by the user.

At step 54, a stopcock may be used to close the syringe. At step 56, theplunger of the syringe may be retracted so that a vacuum is pulled inthe barrel of the syringe. Thus, after step 56, the barrel of thesyringe will include a fluid portion and a vacuous portion. Because thedegassing tool may include a locking mechanism, the plunger may belocked into a fixed position, thereby maintaining the vacuum in thebarrel of a syringe.

With a vacuum maintained in the barrel of the syringe, the medication orother fluid in the barrel may be degassed at step 58. Degassing of themedication or other fluid may be accomplished in a variety of ways. Forexample, according to an embodiment of the present invention, the entiresyringe/degassing tool combination may be manually shaken by the user sothat air or other gasses that have been dissolved in the medication orother fluid may be released into the vacuum. Shaking thesyringe/degassing tool increases the amount of surface area of the fluidseen by the vacuum, thereby allowing a greater amount of gas to beexpelled from the fluid into the vacuum.

Once the medication has been sufficiently degassed, the stopcock may beopened so that gasses residing in the previously evacuated area of thebarrel of the syringe may be released through a needle in the syringe.If desired, steps 54 through 60 may be repeated to maximize the amountof degassing of the medication or other fluid. For example, according toan embodiment of the present invention, three cycles of steps 54 through60 may be sufficient to adequately degas a fluid before injecting thefluid into a patient or a pump or reservoir implanted in a patient.

Subsequent to the last implementation of step 60, a needle in thesyringe may be inserted into a negative pressure device implanted in thepatient. The negative pressure device may be, for example, a pump, suchas an insulin pump, for example, or other negative pressure reservoir.Because the implanted device is a negative pressure device, the fluidresiding in the barrel of the syringe will normally enter the patientdue to the prevailing, sufficiently greater pressure of the externalenvironment. However, a query may be made at step 64. If the fluidentered the patient, the procedure is complete at step 68. If the fluiddid not enter the patient, the syringe may be pierced by the piercingelement so that air enters the barrel of the syringe and increases thepressure on the fluid in the barrel of the syringe. This should causethe fluid to enter the negative pressure device implanted into thepatient.

If fluid exists in the implanted device prior to degassing andfilling/refilling the device, it may be desirable to remove the oldfluid before filling the device with new fluid. A generalized method ofusing a degassing tool to remove fluid from a negative pressure deviceaccording to an embodiment of the present invention is shown in FIG. 4.At step 70, a syringe is inserted into a degassing tool such as, forexample, the degassing tool shown in FIG. 1. At step 72, a stopcock maybe inserted onto the syringe and closed to seal the syringe. At step 74,the plunger of the syringe may be retracted to pull a vacuum in thebarrel of the syringe.

At step 76, a needle may be inserted onto the stopcock. At step 78, theneedle is then inserted into the patient so that it makes contact with afill/refill port on the implanted device. At this point, the pressure inthe negative pressure device should be greater than that in the barrelof the syringe, which is at vacuum. Next, at step 80, the stopcock isopened and the fluid in the implanted device should flow freely into thebarrel of the syringe.

A degassing tool 90 according to another embodiment of the presentinvention is shown in FIG. 5. The degassing tool 90 in FIG. 5 is shownwith a syringe 102 having a plunger 104 inserted. The embodiment of theinvention shown in FIG. 5 includes, but is not limited to a holder 92for holding the syringe 102. Affixed to the holder 92 is an extensionpiece 94. The extension piece 94 may be hingedly or otherwise moveablyattached to the holder 92.

Attached to the extension piece 94 is a locking post 96 which ishingedly or otherwise movably attached to the extension piece 94. Thedegassing tool 90 shown in FIG. 5 may also include a lever 98 and apiercing mechanism 100, similar to the lever and piercing mechanismshown in the embodiment of the invention of FIG. 1.

When using the embodiment of the invention shown in FIG. 5, the syringe102 may be positioned into the holder 92. The plunger 104 may then bedrawn back away from the holder 92 so that a vacuum is pulled within thebarrel of the syringe 102. The extension piece 94 and the locking post96, being hingedly or otherwise moveably attached to each other, and theextension piece 94 being hingedly or otherwise moveably attached to theholder 92, may be rotated away from the syringe and the plunger in orderto draw the plunger 104 back. Once the plunger 104 has been drawn to thedesired position, the extension piece 94 and the locking post 96 may berotated toward the plunger 104 so that the locking post 96 prevents theplunger 104 from moving back into the barrel of the syringe 102. Thus,the vacuum pulled within the barrel of the syringe is maintained.

FIGS. 6 a and 6 b show perspective views of the holder 92 and theextension piece 94, respectively. The holder 92 may be sized and shapedto accept standard syringe sizes that are common in the industry. Theextension piece 94, according to the embodiment of the invention shownat FIG. 6 b, is formed as a “double L” shape to facilitate a moveableconnection to the holder 92 and the locking post 96.

While particular embodiments of the present invention have been shownand described, it will be obvious to those skilled in the art that theinvention is not limited to the particular embodiments shown anddescribed and that changes and modifications may be made withoutdeparting from the spirit and scope of the appended claims.

1-25. (canceled)
 26. A method for degassing a fluid comprising:inserting a syringe into a degassing tool; drawing a fluid into thesyringe; closing the syringe; retracting a plunger of the syringe tocreate a vacuum in a portion of a barrel of the syringe; locking theplunger using the degassing tool; expelling gas dissolved in the fluidinto the vacuum in the portion of the syringe; and expelling the gas inthe vacuum out of the syringe.
 27. The method of claim 26, wherein thefluid is insulin.
 28. The method of claim 26, wherein the syringe isclosed with a stopcock.
 29. The method of claim 26, wherein the plungeris disposed in a slidable portion of the degassing tool.
 30. The methodof claim 26, wherein expelling gas dissolved in the fluid into thevacuum in the portion of the syringe comprises shaking the syringe whilethe syringe is disposed in the degassing tool.
 31. The method of claim28, wherein expelling the gas in the vacuum out of the syringe comprisesopening the stopcock.
 32. A method for degassing a fluid and insertingthe fluid into a negative pressure device implanted in a patientcomprising: inserting a syringe into a degassing tool; drawing a fluidinto the syringe; closing the syringe; retracting a plunger of thesyringe to create a vacuum in a portion of a barrel of the syringe;locking the plunger using the degassing tool; expelling gas dissolved inthe fluid into the vacuum in the portion of the syringe; expelling thegas in the vacuum out of the syringe; inserting the syringe into thenegative pressure device; and opening the syringe.
 33. The method ofclaim 32, wherein the fluid is insulin.
 34. The method of claim 32,wherein the plunger is disposed in a slidable portion of the degassingtool.
 35. The method of claim 32, wherein expelling gas dissolved in thefluid into the vacuum in the portion of the syringe comprises shakingthe syringe while the syringe is disposed in the degassing tool.
 36. Themethod of claim 32, further comprising piercing a portion of the barrelof the syringe.
 37. The method of claim 36, wherein the portion of thebarrel of the syringe pierced is adjacent the fluid and opposite theimplanted device.
 38. The method of claim 36, wherein the barrel of thesyringe is pierced such that no pieces of the barrel dislodge into thefluid.
 39. A method for filling a negative pressure device comprising:inserting a syringe into a degassing tool; closing the syringe;retracting a plunger of the syringe to create a vacuum in a portion of abarrel of the syringe; locking the plunger using the degassing tool;inserting the syringe into the negative pressure device; and opening thesyringe.
 40. The method of claim 39, wherein the syringe is insertedinto the negative pressure device using a needle.